Skyrim:Scrolls

Scrolls are magical documents that can be used to cast spells. Anyone can use a scroll, regardless of magic skill, and casting a scroll does not use any magicka. However, each scroll can only be used once. With the exception of the Scroll of Blizzard, using a scroll does not provide any magic skill experience.

You cannot learn the spell contained in a scroll to cast later, you need a spell tome for that.

Some scrolls can be purchased from spell merchants, who will have a random selection of standard scrolls they might sell. Note that scrolls are often found hiding in between rolls of paper, so it might be worthwhile scanning through them. Most scrolls are not found in random treasure, but are only available as fixed loot.

Scrolls can only be sold to spell merchants and general good merchants.

To use a scroll, first select it in the inventory (or via the Favorites quick menu). This assigns it to a hand. Some scrolls require both hands. The assigned hand glows with a color or animation related to the scroll's spell.

Then, hold down the attack button. A spell-casting animation takes place, during which the attack button must continue to be held down until it finishes. For some scrolls, this may take several seconds. Higher-level scrolls take longer to cast. Unlike with casting learned spells, the player cannot walk or run during the casting. Upon release of the attack button, the scroll's spell is unleashed. If the caster is interrupted (e.g. by a weapon blow or by a shout) before the casting is complete, then the spell is not cast, the scroll is not consumed, and the caster must start casting from the beginning. This can make it difficult to use a scroll in close combat.

For 30 seconds, opponents in melee range take 10 points per second fire damage. Targets on fire take extra damage. The player will be injured, and followers and perhaps others in the area may take damage:

Dragonborn adds a special type of scrolls called spider scrolls, which can only be created in the imbuing chamber in White Ridge Barrow. These can be equipped in either hand and are thrown rather than cast. As with standard scrolls, anyone can use a spider scroll regardless of magic skill, and using one does not use any magicka; however, each spider scroll can only be used once.

Scrolls that reanimate a corpse will allow for the body to remain intact after the spell wears off, allowing the corpse to be reanimated an unlimited number of times. This is unlike reanimation spells, where the body will disintegrate after the spell wears off.

This issue has been addressed by version 2.0.9 of the Unofficial Skyrim Patch; reanimated corpses will disintegrate after the spell wears off.